Internal-combustion engine installation



2 `Sheets-.Sheet 1 A. l-L R.- FEDDEN Erm.

piled Jan. v14, 1942 Y INTERAL-COKBUSTION ENGINE INSTALLATION Timm 2 QW/.1|

' A. H. R. FEDDEN Erm.v 2,356,452

Aug. 22, 1944. i

' INTERNAL-COMBUSTION ENGINE INSTALLATION 2 Sheets-Sheet 2 Filed Jan. 14, 1942 4 w44 +Mw atente'd ug. 22, l944 INTERNAL-COMBUSTION ENGINE INSTALLATION Alfred Hubert Roy Fedden, Bristol, England, and

' Frederick Metcalf Thomas, North Adams, Mass.,

assignors to The Bristol Aeroplane Company Limited, Bristol, England, a British company Application January 14, 1942, serial N6. 426,774 In Great Britain January 17, i941 Claims.

In' an air-cooled internal-combustion engine installation wherein the engine is totally enclosed, a considerable part of the exhaust pipes or ducts necessarily lies within the enclosure, and since it is at a high temperature it must be eiectively isolated from the ducts whereby the cold air which is required to cool the engine is introduced, and also from the. air which is Vto be used for combustion. IlI'he cold air to be used for different purposes is conveniently conveyed by ducts which isolate the various ows from one another, and nally the air which has been heated, as for example by cooling the enginemust also be disposed of. The object of this invention is to Iprovide an improved construction'and arrangencient of ducts for all these purposes.

According to this invention .in an air-cooled internalcombustion engine installation, the ducts for cold air, heated air, and exhaust gases are so disposed that a cold air. duct and an exhaust duct are separated from one another by a heated-air duct. With this arrangement the minimum temperature-diierence is obtained between any two adjacent ducts so that the trier of heat between them is also kept to a minimum, and the maximum economy of space and simplicity of manufacture is obtained.

-Preferably'the various ducts are arranged one within another, so that the duct for the exhaust gases is surrounded by a. space constituting a duct for the heated outgoing air, and the latter is surrounded by ra. space constituting a duct for the cold incoming air.

According to another feature of thisy inven-v tion, the heated-air duct surroundingl the exhaust duct is extended throughoutthe full length thereof, thereby ensuring a considerable cooling of the exhaust gases by transfer of heat to the outgoing air. This air can be discharged to mix with the outgoing exhaust gases at the outlet orifice in `such a manner as to' give a reaction thrust from theircombined momentum, and to eect an additional pressure drop inthe cooling air exit thereby assisting the iiow of such air. The invention is advantageously used in con- (ol. 24assi Like reference characters indicate like parts throughout these drawings.

, In the power plant installation illustrated, two radial internal-combustion engines it are A mounted inthe fuselage il of-an aircraft with gether by suitable gearing from Which g-"a-;,drive is transmitted. by two shafts i3 extendinglatrff ally from the yfuselage within the wingsA Eitto airscrews mounted at any convenient point in the wings" at each side of the fuselage.

The engines are totally enclosed within the fuselage and there is provided in each wing an' air-duct i5 extending from an opening i6 in the leading edge of the wing to the side of the chamber l2 between the two engines.

Each engine is enclosed in a substantially cy-l lindrical cowl il and theZ adjacent ends of these cowls are joined together to 4constitute the peripheral wall of the chamber l2 into which the ducts i5 lead. The other ends of the two barrels.

v'the cowl il `and the partition iand theni to cowls are completely closed by end-plates i8.

Within each of the cowls il there is mounted s cylindrical partition le which separates the Vlcylinder-heads 2t from the cylinder-barrels 2l,

and each partition is terminates short of the end-plate it so as to. provide communication between the annular 'space around'the cylinderheads tothe internal space around the cylinder- Conveniently also the adjacent ends of lthe two partitions I9 are joined together in the chamber l2. The exhaust gases from each engine ow into a collecting ring 22, these two rings being situated in the space l2 between the two engines.

' The air supply to the engine enteringat the inlets .Itis conveyed `by the ducts i5 and enters the chamber l2 at each side, and is then made to dow first over the cylinder-heads 20 between return inside the partition i9 round the cylinderjunction with those described in the specifica- I tions of United States Applications Nos. 4426,775

and 426,776, and such an arrangement is illustrated in the accompanying drawings as one ein bodiment of the present invention.

in these drawings: Figure i is 'a sectional plan of craftshqwing the power plantinstallation and the ducts leading to and from it, j

Figure 2 is a sectional elevation on the lin 2-2ofrigure1, Figures 3, 4' and 5 are detailed views being rel spectively sections' on the lines 3 3, B--li and oi Figure 1.-

.part of an airbarrels 2i as is more fully'described-in the speci- -ncation of United yStates .application No. 427,775. 'I'his air which has lbeen heated, by cooling the4 cylinders, then iiows outI by conduits 25 opening from each side of the partition i9 ancleilztendingl rearwardly inside the wing (see Figurez) to an v outlet 28 on therunder side thereof near the trailing edge. The Iexhaust gases'v are led out from the two collecting rings 22 aforesaid by tail-pipes 24, one allocated to each ring and sit- 5 u ated respectively insidethe two heated-airfoutlet ducts 25. Preferably these tail-pipes as extend to `outlets 29 at theendof the ducts 25 as shown in Figure 2i.

It will be see'n thatthe cold air duct I5, aty

the part adjacent the cowling il surrounds the 24 are each situated within a duct 25 and are therefore separated by it from the cold incoming air 'so that there can be no direct transfer of heat from the hot exhaust gases to the incoming cooling ain Oil coolers"2 for the engines may be arranged in separate ducts 2l which are supplied with air from the inlets iS respectively, andthe heated air lfrom these coolers passes on and enters the heated-air duct 25 as shown in Figure l.

It is not essential that the cold air duct should entirely surround the heated-air "duct, but.

merely thatit should'not be at any point -in direct contact-with the exhaust gases or the exhaust ducts, and as will be seenfrom Figures 2 and 3, the cold air duct i5 only partly surrounds theheated-air duct 2S at that point in assente vhentai-air 'ouder duct se, and that the tau-pipes engine and entirely enclosed in the heated-air ducts respectively, two ducts for cold air which extend from air-intakes symmetrically disposed with respect to the engine chamber in the leads ing edges of the wings to enter the engine chamber at opposite sides and which partially surround the heated-air ducts where they enter the chamber, and partitioning means' within the chamber to cause the cold air admitted through the cold air ducts to flow over each engine away from the space between the engines and then to iow over each engine in the reverse direction into .the heated air ducts.

4. The combination with an aircraft having a fuselage and wings one on either side ofv the fuselage, of an engine chamber in the portion of the fuselage between the wings, two air-cooled internal combustion engines mounted in tandem order conveniently to accommodate the exhaust pipei and the driving shaft I. The exhaust tail-pipe 24 however, is throughoutl its length entirely surrounded by the 'heated-air outlet duct 2t as shown in Figures 4 and. '5 as well'as inl'figuresLZandS. A We claim: y 1. Invan aircraft having a wing, the combination with an enclosed engine chamber, Aan airlcooled internal-combustion engine in the .chamber, a duct for 'heated air'extending laterallyfrom the chamber through the wing to an airoutlet near the trailing edge of the wing, a duct for exhaustgases extending from the engine entirely within the heated-air duct, aduct for cold air extending from an air-intake at the leading edge of the wing to enter the engine chamber laterally and at least partly surround A the heated-air duct at the place where it enters air ducts and with the iirst space at the ends of thechamber and in which cylinder barrels the chamber, and partitioning meanswithin-the chamber to cause the cold air admitted 'through the cold air duct to now over the engine nrst in one direction and then in the reverse direction,

to theheated air duct.

`2. In`v an aircraft, the combination with an' engine chamber, an air-cooled internal-combustion plant within the chamber, and a wing on either side of the chamber, of two ducts for heated air4 extending oppositely and symmetrically from. the chamber into thel Wings and to outlets symmetrically disposed with respect to the chamber near the trailing edges of the wings, two, ducts for exhaust gases leading from the plant one entirely within each heated-'air duct,

in the chamber lengthwise of the fuselage, two ducts fo'r heated air which extend oppositely and symmetrically from the space between the two engines in the chamber through the wings to outlets disposed fsymmetrically near the trail= ing edges of thegwings, two exhaust ducts leadq ,ing onefrom each Iengine throughand entirely within a d iierent one of the heated air ducts,

two ducts for cold air disposed one in each wing 4to extend from air intakes symmetrically dispbsedin the leading edges of the wings to enter the engine chamber at opposite sides and partly to surround the heated air ducts where they enter the chamber, and partitioning means with in the chamber to divide 1t into s. space with which the cold `air ducts communicate and in which cylinder heads of the engine are located, and a space which communicates with the heated and. exhaust manifolds of the engine/are located.

5*. The combination with an aircraft having a fuselage and two wings one on either side oi the fuselage, of an engine chamber in thev fuselagev betweenthe wings, a cylindrical partition supported within the chamber with its axis-disposed lengthwise of the chamber and the fuselage to divide the chamber into an inner portion andan outer portion that communicate only at the ends of the chamber, two air-"cooled in- 'teruel-combustion engines having radially artwo ducts for cold air which extend one within each wing from two 4air-intakes disposed sym- I metrically with respectrto the engine chamber in the leading edges of the wings and which enter the chamber at opposite sides and each at least partially surrounds thev heated-airduct on the same side of the chamber at the placev where it 'enters 'the chamber,` and partitioning means within the chamber to cause the cold air ad-4 mitted through-the cold air ducts to ow over the engine rst in one direction and then in the reverse direction to the heated air ducts.

3. In 'an aircraft, the combination `with an in the chamber, and a wing on either'side of the chamber, oi two ducts for heated air which extend oppositely and symmetrically from th'e space between the two engines in the chamber through the wings to outlets symmetrically disposed near the trailing. edges of the wings, two' ducts f or exhaust gases leading one fromeach engine chamber, two engines spaced apart with- I ranged cylinders and mounted'in the chamber with their axes coaxial with the partition and their cylinders extending from the inner portion of the chamber through the partition, two

air ductsextending respectively from air intakes disposed symmetrically with respect to the inselage in the leading edges ofthe wings, located wholly onejn each wing and opening into the outer part of the chamber on opposite sides thereof and between the engines, two heated air ducts opening into the portion of the chamber v within the partition between the engines and on opposite sides of the partition,- extending oppo- -sitely through the walls of the chamber at the place where the cold air ducts enter to be partly 'surrounded by the cold air ducts and extending within the wings to outlets disposed symmetrically with respect to the fuselage in the rear edges of the wings, and ducts for exhaust gases extending one from each lengine within the partition and through and entirely within the heated air ducts.

ALFRED HUBERT ROY FEDDEN. -FRmERICK METcAm THOMAS. 

